Monthly Archives: November 2019

Tropical Storm Nakri Brings Wind, Rain to Vietnam and Cambodia

Tropical Storm Nakri brought wind and rain to Vietnam and Cambodia on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Storm Nakri was located at latitude 13.0°N and longitude 108.9°E which put it about 20 miles (35 km) west of Tuy Hoa, Vietnam.  Nakri was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 992 mb.

The center of Tropical Storm Nakri made landfall on the coast of Vietnam near Tuy Hoa on Sunday.  The maximum sustained wind speed at the time of landfall was 65 m.p.h. (105 km/h).  Nakri moved slowly toward the west after it made landfall.  Tropical Storm Nakri has been weakening slowly since the center moved over land.  The heaviest rain was falling in bands in the western half of the circulation.  Heavy rain was falling over portions of southern Vietnam and northeastern Cambodia.  The strongest winds were occurring in the eastern half of Nakri which was still over the South China Sea.  Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Tropical Storm Nakri will move south of a ridge over high pressure over the South China Sea and southeast Asia.  The ridge will steer Nakri toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Nakri will continue to weaken as it moves farther inland.  On its anticipated track Nakri will drop locally heavy rain over parts of southern Vietnam, northern Cambodia, southern Laos and eastern Thailand.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Bulbul Makes Landfall Southeast of Kolkata

Tropical Cyclone Bulbul made landfall southeast of Kolkata, India on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Bulbul was located at latitude 21.8°N and longitude 89.2°E which put it about 75 miles (120 km) southeast of Kolkata, India.  Bulbul was movign toward the east-northeast at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 967 mb.

Tropical Cyclone Bulbul made landfall on the coast of West Bengal southeast of Kolkata, India on Saturday.  The India Meteorological Department’s weather radar in Kolkata indicated that the eye of Bulbul crossed the coast of West Bengal.  Tropical Cyclone Bulbul was the equivalent of a hurricane/typhoon at the time of landfall.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

The northern section of the eyewall of Tropical Cyclone Bulbul moved across the southeastern part of West Bengal and the southwestern portion of Bangladesh.  Thunderstorms in the eyewall were dropping heavy rain over those areas.  Bands of showers and thunderstorms in the northeastern part of Bulbul were also dropping heavy rain over other parts of Bangladesh.  The heavy rain could cause floods in some locations.  Southerly winds blowing around the eastern side of Tropical Cyclone Bulbul were pushing water toward the coast.  Bulbul could cause a storm surge of 6 to 9 feet (2 to 3 meters) in some coastal locations.

Tropical Cyclone Bulbul will move around the northwestern part of a ridge of high pressure over southeast Asia.  The ridge will steer Bulbul toward the east-northeast during the next several days.  On its anticipated track Tropical Cyclone Bulbul will move over coastal areas of Bangladesh between Dhaka and Chittagong.  Bulbul will weaken gradually as the center moves over land.  The wind speeds and storm surges will gradually decrease.  Tropical Cyclone Bulbul will continue to drop heavy rain over southern Bangladesh during the next 24 hours and the threat of fresh water floods will remain.

Nakri Strengthens to a Typhoon and Moves Toward Vietnam

Former Tropical Storm Nakri strengthened into a typhoon and started to move toward Vietnam on Friday.  At 4:00 p.m. EST on Friday the center of Typhoon Nakri was located at latitude 12.9°N and longitude 114.9°E which put it about 395 miles (635 km) east of Quy Nhon, Vietnam.  Nakri was moving toward the west at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 977 mb.

The distribution of thunderstorms around Typhoon Nakri was asymmetrical.  A broken ring of showers and thunderstorms surrounded the center of Nakri.  The strongest thunderstorms were in the southern portion of the ring.  Most of the strongest rainbands were in the southern half of the typhoon, although there was one strong rainband along the northern periphery of the circulation.  Many of the other bands on the eastern and northern sides of Typhoon Nakri consisted primarily of showers and lower clouds.  It appeared that sinking, drier air was limiting the development of thunderstorms in the northern half of the circulation.

In spite of the effects of the drier air, the size of the circulation around Typhoon Nakri increased on Friday.  Winds to typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.

Typhoon Nakri will be moving through an environment marginally favorable for intensification during the next 12 to 24 hours.  Nakri will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southern side of an upper level ridge over southeast Asia and the South China Sea.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  Drier air to the north of Typhoon Nakri will also inhibit intensification.  Nakri is likely to maintain its intensity during the next day or so, but it could start to weaken if the wind shear increases or more drier air sinks over the circulation.

The ridge over southeast Asia and the South China Sea will steer Typhoon Nakri toward the west during the next two to three days.  On its anticipated track Typhoon Nakri could approach the coast of Vietnam in about 48 hours.  Typhoon Nakri could bring gusty winds and a storm surge for the central coast of Vietnam.  Nakri could drop locally heavy rainfall when it moves inland and flash floods could occur in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Halong was speeding away from Miami Tori Shima, Japan.  At 4:00 p.m. EDT on Friday the center of Tropical Storm Halong was located at latitude 30.9°N and longitude 161.1°E which put it about 580 miles (935 km) northeast of Minami Tori Shima, Japan.  Halong was moving toward the northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 983 mb.

Tropical Cyclone Bulbul Moving Toward Kolkata

Tropical Cyclone Bulbul moved toward Kolkata, India on Friday.  At 4:00 p.m. EDT on Friday the center of Tropical Cyclone Bulbul was located at latitude 19.7°N and longitude 87.8°E which put it about 225 miles (360 km) south of Kolkata, India.  Bulbul was moving toward the north at 8 m.p.h. (13 k/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 861 mb.

It appeared that Tropical Cyclone Bulbul may have pulled drier air from India around the southern and eastern sides of its circulation.  Rainbands in those parts of the tropical cyclone consisted primarily of showers and lower clouds.  Microwave satellite images provided some evidence of an eye at the center of circulation.  A ring of thunderstorms around the eye exhibited weaker sections on the eastern side of the eye.  The strongest winds were occurring in the ring of storms.  Other strong bands of thunderstorms were present in the western half of the circulation.

Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Tropical Cyclone Bulbul.  Winds to tropical storm force extended out 140 miles (220 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Bulbul was 16.5.  The Hurricane Size index (HSI) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 29.7.  Bulbul was capable of causing serious damage.

Tropical Cyclone Bulbul may be near its maximum intensity.  Bulbul will move over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy in the upper Bay of Bengal to support further intensification.  However, the introduction of drier air into the southern and eastern parts of the circulation will inhibit the development of thunderstorms in those portions of the tropical cyclone.  Bulbul will move under the western end of an upper level ridge over southeast Asia.  The ridge will produce some vertical wind shear which will also inhibit further intensification.  Tropical Cyclone Bulbul could weaken when it nears the coast around the northern Bay of Bengal.

Tropical Cyclone Bulbul will move around the western end of the ridge over southeast Asia.  The ridge will steer Bulbul toward the north for another 18 to 24 hours.  On its anticipated track Tropical Cyclone Bulbul could approach the coast of India south of Kolkata in about 18 hours.  Bulbul will turn more toward the east when it moves around the northwestern part of the ridge in a day or so.

Tropical Cyclone Bulbul could be the equivalent of a hurricane/typhoon when it makes landfall in West Bengal south of Kolkata.  Bulbul will bring gusty winds to the coast of West Bengal and Bangladesh.  Tropical Cyclone Bulbul will be capable of generating a storm surge of up to 6 to 9 feet ( 2 to 3 meters) along portions of the coast around the northern Bay of Bengal.  That area is particularly prone to storm surges.  Bulbul will drop locally heavy rain over parts of West Bengal and Bangladesh when it moves inland.  Locally heavy rain could cause flash floods in some locations.

Tropical Storm Nakri Stalls West of the Philippines

Tropical Storm Nakri stalled west of the Philippines on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Storm Nakri was located at latitude 12.8°N and longitude 116.8°E which put it about 290 miles (465 km) west-southwest of Manila, Philippines.  Nakri was moving toward the south at 2 m.p.h.  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 980 mb.

Tropical Storm Nakri meandered slowly west of the Philippines on Thursday.  The structure of Nakri did not change a lot during the day.  There was a distinct low level center center of circulation.  Thunderstorms were forming on the south side of the center and the strongest winds were occurring in those thunderstorms.  Thunderstorms were also developing in bands in the southern half of Tropical Storm Nakri.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Storms south of the center generated upper level divergence that pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation.

Tropical Storm Nakri will move through an environment favorable for intensification during the next 24 to 36 hours.  Nakri mixed cooler water to the surface during the period when it meandered west of the Philippines, but it will move over water where the Sea Surface Temperature is near 29°C when it starts moving.  Tropical Storm Nakri will move southeast of an upper level ridge over southeast Asia.  The ridge will produce easterly winds which will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but it will not be strong enough to prevent Tropical Storm Nakri from strengthening.  Nakri will likely become a typhoon on Friday or Saturday.

Tropical Storm Nakri has been in an area where the steering winds have been weak and it has moved little during the past 24 hours.  The ridge over southeast Asia will strengthen and it will steer Nakri toward the east during the next 72 hours.  On its anticipated track Tropical Storm Nakri could approach the coast of Vietnam in less than 72 hours.  Nakri is likely to be a typhoon when it approaches the coast of Vietnam.

Elsewhere over the Western North Pacific Ocean, Typhoon Halong was passing north of Minami Tori Shima, Japan.  At 10:00 p.m. EST on Thursday the center of Typhoon Halong was located at latitude 27.2°N and longitude 154.4°E which put it about 175 miles (280 km) north of Minami Tori Shima, Japan.  Halong was moving toward the northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 968 mb.

Tropical Cyclone Bulbul Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Bulbul strengthened into the equivalent of a hurricane/typhoon over the Bay of Bengal on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Bulbul was located at latitude 16.5°N and longitude 87.5°E which put it about 400 miles (645 km) south of Kolkata, India.  Bulbul was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 976 mb.

The circulation around Tropical Cyclone Bulbul exhibited greater organization on Thursday.  Microwave satellite imagery indicated that an eye was forming at the center of circulation.  A ring of thunderstorms was developing around the eye and the strongest winds were occurring in that ring of storms.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Bulbul.  The strongest rainbands were in the northwestern half of Bulbul.  Winds to hurricane/typhoon force extended out 15 miles (25 km) from the center of circulation.  Winds to tropical storm force extended out 145 miles (230 km) from the center.

Tropical Cyclone Bulbul will move through an environment favorable for intensification during the next 24 to 36 hours.  Bulbul will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge over southeast Asia.  The upper level ridge will produce southerly winds which will blow toward the top of the circulation.  There will be southerly winds at all levels and there will not be a lot of vertical wind shear.  Tropical Cyclone Bulbul will intensify during the next 24 to 36 hours.

The ridge over southeast Asia will steer Tropical Cyclone Bulbul toward the north during the next several days.  On its anticipated track Tropical Cyclone Bulbul could approach the area around Kolkata, India in less than 48 hours.  Bulbul could be the equivalent of a hurricane/typhoon when it approaches the coast around the northern end of the Bayof Bengal.

Tropical Cyclone Bulbul Strengthens over Bay of Bengal

Tropical Cyclone Bulbul strengthened over the Bay of Bengal on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Bulbul was located at latitude 14.8°N and longitude 89.9°E which put it about 520 miles (840 km) south of Kolkata, India.  Bulbul was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 985 mb.

A low pressure system that was formerly designated at Tropical Storm Matmo when it was over the South China Sea moved across southeast Asia and over the Bay of Bengal during the past few days.  The low pressure system became nearly stationary west of the Andaman Islands.  More thunderstorms began to develop and bands began to form on Tuesday.  The low pressure system strengthened on Wednesday and the India Meteorological Department designated the system as Tropical Cyclone Bulbul.

The circulation around Tropical Cyclone Bulbul was still organizing on Wednesday night.  More thunderstorms were developing around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Bulbul.  The stronger rainbands were in the western half of the circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center.

Tropical Cyclone Bulbul will move through an area favorable for intensification during the next 48 hours.  Bulbul will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge over southeast Asia.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Bulbul is likely to strengthen into the equivalent of a hurricane/typhoon within 36 to 48 hours.

The ridge over southeast Asia will steer Tropical Cyclone Bulbul toward the north during the next several days.  On its anticipated track Tropical Cyclone Bulbul will approach the coast around the northern Bay of Bengal in two or three days.  Bulbul could be the equivalent of a hurricane/typhoon when it approaches the coast.

Elsewhere, a much weaker Tropical Cyclone Maha neared the west coast of India.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Maha was located at latitude 20.0°N and longitude 70.2°E which put it about 75 miles (120 km) southwest of Dui, India.  Maha was moving toward the east-northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.  Tropical Cyclone Maha will drop rain of southern Gujarat on Thursday.

Weakening Tropical Cyclone Maha Moves Back Toward India

A weakening Tropical Cyclone Maha moved back toward India on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Maha was located at latitude 19.8°N and longitude 66.7°E which put it about 425 miles (690 km) west of Mumbai, India.  Maha was moving toward the east at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 985 mb.

An upper level trough over southwest Asia was producing westerly winds which were blowing toward the top of Tropical Cyclone Maha.  Those winds were creating strong vertical wind shear which was causing Maha to weaken steadily.  Tropical Cyclone Maha weakened to the equivalent of a tropical storm on Tuesday night.  There was no longer an eye at the center of Maha.  Thunderstorms were forming in rainbands east of the center of circulation.  Bands in the other parts of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 75 miles (120 km) from the center of circulation.

The westerly winds were also steering Tropical Cyclone Maha back toward India.  On its anticipated track Maha could approach the coast of India between Mumbai and Diu in about 48 hours.  Tropical Cyclone Maha is likely to have weakened to the equivalent of a tropical depression by the time it nears the coast.

Typhoon Halong Intensifies into Equivalent of Cat. 5 Hurricane

Typhoon Halong intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Typhoon Halong was located at latitude 20.4°N and longitude 150.6°E which put it about 345 miles (560 km) southwest of Minami Tori Shima, Japan.  Halong was moving toward the north-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h).  The minimum surface pressure was 900 mb.

Typhoon Halong intensified into one of the strongest tropical cyclones of 2019 over the Western North Pacific Ocean on Tuesday.  There was a circular eye with a diameter of 15 miles (24 km) at the center of Halong.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Halong.  Storm near the core were generating strong upper level divergence which was pumping mass away to the northeast of the typhoon.

The circulation around Typhoon along was compact and symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Halong was 42.2.  The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 51.6.

Typhoon Halong has probably reached its peak intensity.  Halong will move over water where the Sea Surface Temperature is near 29°C.  However, an upper level trough near Japan will approach Typhoon Halong from the northwest.  The trough will produce strong southwesterly winds which will start to increase the vertical wind shear.  More wind shear will cause Halong to weaken.

The upper level trough will start to steer Typhoon Halong toward the northeast in 12 to 24 hours.  On its anticipated track Typhoon Halong will pass northwest of Minami Tori Shima on Thursday.  Even though it will weaken, Halong will bring strong, gusty winds and heavy rain.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri developed over the South China Sea between the Philippines and Vietnam on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Nakri was located at latitude 13.8°N and longitude 116.0°E which put it about 380 miles (615 km) west of Manila, Philippines.  Nakri was moving toward the northeast at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.

Although Tropical Storm Nakri is currently moving toward the northeast, it is forecast to move back toward the west later this week.  Nakri will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Nakri could strengthen into a typhoon before it reaches the coast of Vietnam.

Vertical Wind Shear Starts to Weaken Tropical Cyclone Maha

Increased vertical wind shear started to weaken Tropical Cyclone Maha over the Arabian Sea on Monday night.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Maha was located at latitude 19.6°N and longitude 63.7°E which put it about 605 miles (1140 km) west of Mumbai, India.  Maha was moving toward the north at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 958 mb.

Upper level westerly winds of the middle latitudes moved southward over the northern Arabian Sea on Monday night.  Those winds caused increased vertical wind shear and they started to weaken Tropical Cyclone Maha.  The westerly winds began to push the higher clouds toward the east and the eye was no longer visible on infrared satellite imagery.  It also appeared that westerly winds lower in the atmosphere may have been transporting drier air toward the western side of Maha.  The rainbands in the western half of Tropical Cyclone Maha weakened on Monday night and there also appeared to be weakening in the southern part of the eyewall.  The strongest rainband was north of the center of circulation.

The circulation around Tropical Cyclone Maha was fairly small.  Winds to hurricane/typhoon force only extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 95 miles (150 km) from the center.  The small size of Tropical Cyclone Maha means it will weaken more quickly because of the effects of vertical wind shear and drier air.  Maha could weaken to the equivalent of a tropical storm within 24 to 30 hours.

The westerly winds will push Tropical Cyclone Maha back east toward India.  On its anticipated track Tropical Cyclone Maha could approach the coast of India north of Mumbai within three days.  Maha will be a much weaker tropical cyclone by the time it nears India.